-It is resilient, durable, and will not scratch the helmet. -The suction cup with double-sided adhesive protection is not easy to fall off. -Removable silicone suction cup, easy to install and disassemble. -The suction cup can only absorb flat and smooth surface. For matt helmet or gap, only double-sided adhesive can be used. -Suitable for almost any helmet with a smooth surface (please note that this item does not contain a helmet).